A drainage catheter is typically introduced to a drainage site such as an abscess or a cavity in the biliary, nephrostomy, or urinary system using an introducer set. Commercially available drainage catheter introducer sets include a wire guide and a dilator. In use, the wire guide extends from a puncture site or point of entry into the body of a patient, and the dilator is positioned thereover for enlarging the puncture site. Finally, the drainage catheter is introduced into the body over the wire guide and through the dilated puncture site with an introducer sheath to extend from the body cavity to the exterior of the patient.
Alternatively, attempts have been made to introduce a drainage catheter to a drainage site using the one-stick approach, which is performed by positioning the drainage catheter over a stiffening cannula and trocar stylet and advancing the catheter into the body of a patient. A problem with this approach is that the distal end of a flexible drainage catheter tends to be pushed, peeled, or rolled back during introduction through an undilated puncture site. As a result, the flexible drainage catheter is deformed and unusable. Furthermore, additional attempts must be made to introduce a drainage catheter into the body of the patient.
One trocar catheter with a closed distal end formed of a smooth, rigid tip permits one-stick penetration of the chest or stomach wall. The closed end, rigid tip includes fluid openings in the side wall thereof. A problem with the use of this trocar catheter for extending from a drainage site is that it has no means for retaining the catheter inside the drainage site while extending from the patient's body.
Another urological catheter has a closed end, semi-rigid, distal tip surrounded by a balloon. Drainage eyes are positioned proximal the balloon in the side wall of the catheter. Yet another balloon catheter has a closed end, rigid tip member. The balloon is attached to the periphery of a side port in the tip member. Still yet another urethral catheter has a collapsible proximal portion, a distal bladder retention head, and a rigid bladder tube connected to the distal end of the inflatable, bladder retention head. The distal faces of the inflatable, bladder retention head and rigid bladder tube include drainage ports. Still yet a further collapsible, urethral balloon catheter has a thick tip portion for providing stiffness of the catheter during insertion into the bladder. The thick tip portion includes side openings. A problem with each of these balloon catheters is that balloon catheters are typically more difficult and expensive to manufacture than catheters with other retention means such as malecots or pigtails.
Still yet another drainage catheter includes a stiffening inner cannula and trocar stylet for one-stick introduction to the drainage site. The inner cannula has a collar positioned a few millimeters back from the distal end of the cannula for engaging the inner surface of the catheter lumen. As a result, the problem of the distal end of the catheter being pushed back during introduction through an undilated puncture site is minimized. A limitation of the use of this drainage catheter is that the flexible material at the distal-most tip of the catheter, which extends distally from the inner cannula collar, still can be pushed, peeled, or rolled back during introduction into the body of a patient. As a result, the distal-most tip material is deformed and has an enlarged cross-sectional dimension that requires greater insertion force or increased dilation at the puncture site when attempting introduction of the drainage catheter.